I actually had a matching "Definitely" couple that only had one child. I put them together repeatedly, with no baby at the end *sniff* Baby boost prior to each attempt as well. They were restarted.

On another note: I currently have a matching "Not Really" couple. At 35 years of age (they match ages too) they have 6 children. 2 sets of twins, and 2 singletons.

Interesting, no?